This is the full video of the no dig garden construction workshop in Nelson NZ - 2009. Facilitated by Bob Jones and Myk Rushton.

No-dig Organic Gardening

Gardeners traditionally dig, or turn over the top layer of soil before planting to get rid of weeds, and make it easier to use fertilizers and to plant crops. This also speeds up the decomposition of crop residue, weeds and other organic matter. Tilling the soil is often the most strenuous of a gardener’s tasks.

A complex, symbiotic relationship exists between the soil surface and the underlying micro-organisms, however, which contributes to a natural, healthy soil structure. Digging into the bed can interfere with this process and disturb the natural growing environment. It can also cause soil compaction and erosion, and bring dormant weed seeds to the surface where they will sprout.

With ‘no-till’ gardening, once the bed is established the surface is never disturbed. Amendments such as compost, manure, peat, lime and fertilizer are ‘top dressed’, i.e added to the top of the bed where they will be pulled into the subsoil by watering and the activity of subsoil organisms. Weeding is largely replaced by the use of mulch. By adding material in layers, the underlying soil surface remains spongy, making it easy for the young roots of newly planted seedlings to work through the soil. This is similar to the way soil is formed in nature.

Benefits of no-till gardening

Promotes natural aeration and drainage.

Worms and other soil life are important to healthy soil structure, their tunnels providing aeration and drainage, and their excretions bind together soil crumbs. No-till systems are said to be freer of pests and disease, possibly due to a more balanced soil population being allowed to build up in this comparatively undisturbed environment, and by encouraging the buildup of beneficial soil fungi.

Saves water.

Thick layers of mulch allow water to pass through easily while shading the soil. This reduces water lost to evaporation while maintaining a moist growing environment beneficial for root growth.

Reduces or eliminates the need to weed.

Most garden soils contain weed seeds which lay dormant until the soil is disturbed and the seeds become exposed to light. With no-till gardening, these seeds will remain dormant indefinitely. Of course, some weeds will appear in the beds, borne by wind or birds. These weeds are easy to remove by hand if you pull them early in the morning or shortly after watering, while the soil is damp.

Saves time and energy.

Whether you turn your garden beds by hand or use a gas-powered rototiller, you’ll save energy by using the no-till method. Although some effort is required in gathering materials for mulching, and applying the mulch during the growing season, no digging or turning of the soil is required.

No-till gardening helps soil retain carbon.

Healthy topsoil contains carbon-enriched humus and decaying organic matter that provides nutrients to plants. Soils low in humus can’t maintain the carbon-dependent nutrients essential to healthy crop production, resulting in the need to use more fertilizers. Tilling the soil speeds the breakdown or organic matter, which releases nutrients too quickly. A steady, slow release of nutrients is more beneficial to plant growth.

Builds earthworm population.

The moist conditions of the soil beneath mulch creates the ideal environment for earthworms, whose activity aerates the soil and stimulates root growth.

Helps reduce soil erosion.

A lack of carbon in soil may promote erosion, as topsoil and fertilizers are often washed or blown away from garden beds.